V8 Swapping a TJ - 5.2/5.9 Dodge Magnum and 46RE Reliability

As you probably guessed from the title, I'm in the planning stages of swapping in a 5.2/5.9 and 46RE into my 2.5 5 speed TJ and wanted to hear from the Hardline brain trust the reliability/ known issues of these engines and transmissions. The TJ will be a daily driver on 33s with the occasional trip to the woods. I'm a GM guy and know almost zero about these. In shopping for donor trucks, I commonly see these with 200k+ miles on them, so I figured they can't be total boat anchors.

fthe motors had head gasket issues and were gas hogs. Head gasket is a fixable issue but was the most common. the 46re will do ok, but you will need to do a solid build on it and really manage the heat. The dodge trannies from that time frame were not complete turds but they were not the best of the choices out there either. Of course it also depends on tire size, horsepower, driving style etc.

Lil ugly said:

fthe motors had head gasket issues and were gas hogs. Head gasket is a fixable issue but was the most common. the 46re will do ok, but you will need to do a solid build on it and really manage the heat. The dodge trannies from that time frame were not complete turds but they were not the best of the choices out there either. Of course it also depends on tire size, horsepower, driving style etc.

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Good info.

I added this above, but the TJ will be a DD on 33s with light trail use. I want enough power under the hood to not fear for my life when merging on the interstate and my wife wants an automatic, so this is the compromise.

I've got an 01 Ram 1500 4wd 5.2 auto with around 170k miles on it. It has never had anything done but regular maintenance. I have owned several vehicles with the same basic drivetrain. Never had any issues that weren't my own fault from abuse. There are a few guys on here that have road with me in my truck, they can tell you it gets beat on and takes it like a champ.

I had a 97 TJ with a 5.2 Magnum in it it's not that hard of a swap advance adapters has the motor mount you can use a pickup truck computer to run it that will bolt right up the fuel pump for the 4-cylinder at the kids the same as for a V8

Bronco Mike said:

I had a 97 TJ with a 5.2 Magnum in it it's not that hard of a swap advance adapters has the motor mount you can use a pickup truck computer to run it that will bolt right up the fuel pump for the 4-cylinder at the kids the same as for a V8

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I originally wanted to swap in a 5.3, but after reading how well the Magnums integrate with all the stock Jeep stuff I decided to go that route. From all that I've read it looks like a really straightforward swap.

5.9 gets my vote

My jeep had the 4 banger . I used a 5.2 and nv 4500. With a pickup computer all your gauges will work.

Motor choice will come down to what kind of donor vehicle I find once I start shopping. I'll be looking for a 98-2000 Ram 1500 (front axle will be used later for a SAS), but if a ZJ, Durango or Dakota came up I wouldn't turn it down. I wouldn't even turn down a 4.0/ automatic Wrangler if I found a wrecked one for the right price.

Bronco Mike said:

My jeep had the 4 banger . I used a 5.2 and nv 4500. With a pickup computer all your gauges will work. View attachment 117611

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So is it just plug and play and what kind of year span. Wonder if I can do this with the XJ, may skip the 6L that's sitting in a van at work.

The guy that ran Backwoods Offroad was an encyclopedia of mopar he is no longer in business. I sent my wiring harness to him and when it came back it was plug it in turn the key and it was running. The vehicle computer and engine need to be within a few years of each other from like 97 to 2001 I think is correct

Bronco Mike said:

The guy that ran Backwoods Offroad was an encyclopedia of mopar he is no longer in business. I sent my wiring harness to him and when it came back it was plug it in turn the key and it was running. The vehicle computer and engine need to be within a few years of each other from like 97 to 2001 I think is correct

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I've read a lot about him. I'll be doing the wiring myself, especially since he isn't in business anymore.

xjmarc said:

So is it just plug and play and what kind of year span. Wonder if I can do this with the XJ, may skip the 6L that's sitting in a van at work.

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From what I have read Chrysler used a CCD bus system from 97-00 and changed to PCI bus in 2001. If you get a donor engine from those year ranges and swap it into a vehicle of those years yes, its just about plug and play. On Wranglers (and I'm sure XJs), when you swap in a 5.2/5.9 the Wrangler body harness plugs into the Dodge PCM and all gauges, etc. work with no modification. The only real wiring you have to do is to blend the TJ and Dodge harness together to add injectors and other components the TJ doesn't have. I really wanted to do an LS swap, but the Dodge and Jeep parts mesh so well it makes for a really clean swap that doesn't need a lot of 'adapting'. Below is a link to a good writeup: